Diamond-holding tool



y 4.LnuuHoFER V DIAMOND-HOLDING rTOOL May 19; 1942.

Ffiied May 41, 1941 4 INVENTOR `oRNlaY k Patented May 19, 1942 UmsoSTATES PATENT" orties DIAMOND-HOLDING TOOL Julius Dinhofer, New York, N.Y.

Application May 1, 1941, Serial No. 391,235

(CI. 12S-39) 4 Claims.

This invention relates to means for holding diamonds of the characteremployed as grinding-wheel dressing tools and for other purposes.

At the present time, diamonds used for grinding or dressing purposes areusually of irregular shape and are held in a holder in such a mannerthat a selected pointed portion of the stone protrudes from the holderfor contact with the wheel or surface to be trimmed or dressed. Diamondsso held have to be mounted in a holder with considerable care, both fromthe standpoint of selecting the proper portion of the stone to protrudefrom the holder, and from the standpoint of most securely holding thestone in position during the hard use to which` a tool of this nature isput.

In mounting a stone in a holder of the known type, the holder is usuallyprovided with a recess in which the stone is positioned, with a pointedend of the irregularly shaped stone protruding slightly beyond theholder. Then by manipulation of the material of the body of the holder,parts of the material `of the holder are forced around the stone andcaused to embrace the same and hold it firmly. After a period of use,when the point of the stone becomes worn, it is necessary for the stoneto be reset in its holder. This requires the user of the tool to returnitk to the manufacturer, who resets the stone by removal of it from theholder and repositioning and replacement of it therein so that a newpointed surface on the stone will project from the end of the tool.

The object of the present invention is to provide a tool for holding adiamond in which the objections to the present-day structure areeliminated and the efficiency of the tool greatly increased. Moreparticularly, the invention contemplates the provision of a diamond ofregular formation and preferably of octahedron shape and formed with aplurality of similarly shaped pointed ends, and in the provision also ofa diamond-gripping means by which the diamond may be rmly held in a.selected position with any one of such pointed ends protruding from theholder in such a way as to permit its most effective use.

'Ihe invention also contemplates the provision of a releasablediamond-holder by which the user of the tool may, when required, shiftthe position of the diamond within the holder to. thereby enable anyselected one of the pointed ends possessed by the diamond to protrudefrom the tool into operative position. The use of the shape of diamondsuggested and a releasable holder therefor not only incerases thematerial life of the diamond: but enables the same to be adjustedwhenever required by the workman, without necessitating the return ofthe tool to the manufacturer for resetting.

These and numerous other advantages are attained by the structure, amore particular description of which will appear hereinafter' and be setforth in the appended claims.

In the accompanying drawing, forming a part hereof, Fig. 1 is asectional View through a tool constructed in accordance with .theinvention; Fig. 2 is a plan View of the same; Fig. 3 is al sectionalview of the head of the tool, showing the parts thereof in separatedrelation; and Fig.

4 is a perspective view of the diamond used in the tool.

In the manufacture of a diamond-holding tool of the charactercontemplated by the present invention, it is necessary that thediamondsemployed in the tool be of uniform shape to not only enable thesame to be securely held in the holder intended for its reception, butto insure the uniform projection of each pointed end of the diamond fromits holder when placed in either of the several positions in which itmay be held. In the manufacture of diamond-holding tools of knownconstruction, no effort has been made to preshape the diamonds employed,such diamonds being selected at random and utilized to best advantage toenable a pointed end on the selected diamond to project from the holder.

In carrying out the invention, I therefore shape the diamond bygrinding, to form it into uniform shape, I have found the octahedral orbypyramidal shape shown in Fig. 4 to be most desirable. It will be seenthat a diamond so shaped is provided with six pointed terminals, namelythose indicated at l to 6 inclusive. A diamond so shaped is providedwith a four-sided girdle l composed of edges 8, 9, I0 and Il disposed atright angles, said angular girdle constituting means by which thediamond may be. embraced in the holder or tool as shown in Figsfl and 2,and by which rotative shifting of the diamond within the tool, as wellas any shifting movement of the diamond in a directionlongitudinally ofthe body of the tool is prevented.

The tool for holding the diamond is shown in Figs. 1 to 3 inclusive andit will be there seen that the same is provided with a body portion l2having a holding device formed on or attached at one end for engagingand securely holding a diamond of the form disclosed in Fig. 4. Saidholding device includes the four jaws I3, each of said jaws bengnotchedas at I4 and thereby engaging over one of the edges 8, 9, I and Il asclearly shown in Fig. 2, so that the diamond, when held between the fourjaws, is engaged at its four sides and is effectively held againstrotative movement relative to the jaws. It will be noted that when thediamond is held between the four jaws in the manner set forth, one ofthe six pointed ends of the diamond will be disposed between and projectoutwardly from the jaws so that it may be held against a grinding wheelor used for any of the purposes for whcih diamond tools of thischaracter are normally employed.

The jaws I3 are heldin gripping position by means of the clamping memberor ring l5 which is internally threaded for reception upon the threadedportion of the jaws, said ring l5 having an internally tapered surfaceI6 operative against the similar surface l1 on the jaws to force thesame toward one another and hold the diamond securely between them'.

The octahedron or bipyramidal shape of the diamond enables it to be sovpositioned within the jaws that any one of the pointed ends on thediamond may be positioned outermost and employed as the grinding ordressing element. Thus, when one of the points becomes worn after use,it is merely necessary to loosen the diamond in the holder and shift itto bring another of the points of the same into projected or outermostposition. Since the diamond, in the form shown, is provided with sixsimilar points which may be successively used by repositioning thedi-amond in the holder, it will be apparent that the useful life of thediamond will be long and this will more than compensate for the time andeiort expended in originally grinding the dia mond into uniformoctahedron shape.

Moreover, since the diamond may be shifted from one possession toanother by the tool owner, and need not leave his possession at any timefor adjustment or re-setting of the diamond, the. tool is of increasedvalue bec-ause of the fact that it remains constantly at hand and in thepossession of the owner. Additionally, since the diamonds provided forthe holder are all of uniform shape, the holder will last indefinitely,While I have shown the holder of a-certai structure and provided withfour jaws to accomaaeaa'eo modate -a diamond of the octahedron shape, itwill be obvious that both the holder and diamond therefor may be ofother shape, and other modifications may be made without departing fromthe spirit of the invention.

What I claim is:

1. A diamond-holding dressing tool comprising a diamond of octahedralform, and a holder in which the same is mounted, said holder including aplurality of jaws for engaging the girdle of the diamond on four sidesonly to thereby grip the diamond and hold the same with all pointed endsof the diamond projecting between the jaws.

2. A diamond-holding tool comprising, a diamond of octahedral form, aholder in which said diamond is gripped, said holder comprising aplurality of spaced jaws notched to engage over the girdle of thediamond and constituting the sole means of supporting the diamond, thediamond having a plurality of pointed ends, all of which are disposedbetween and not engaged by the jaws.

3. A diamond-holding tool comprising, a diamond of octahedral form, aholder in which said diamond is gripped, said holder comprising aplurality of spaced resilient jaws notched to engage over the girdle ofthe diamond, the jaws being so spaced apart that all of the pointed endson the diamond are disposed between and not engaged by the jaws, andmeans for causing the jaws to be exed toward one another.

4. A diamond-holding tool comprising, a diamond of octahedral form, aholder in which the same is removably held, said holder having a baseportion, four spaced resilient gripping jaws extending therefrom, eachofsaid 'jaws being provided with an angular notch adapted to engage overthe girdle of the diamond, the four jaws constituting a sole means ofsupporting the diamond between them, the portions of the jaws engagingthe diamond being spaced from one another whereby one pointed end of thediamond protrudes outwardly from the ends of the jaws and other pointedends of the diamond are located between and out of Contact with thejaws, and means for forcing the jaws toward one another to cause them toclamp the diamond Y-between them.

JULIUS DINHOFER.

